The entire point of this car—an idea Honda’s been kicking around for nearly three decades—is the hydrogen fuel cell.

That stack of cells will produce about 175 horsepower, and sent the car more than 300 miles between refueling stops.

Hydrogen is the most abundant element in the universe and there are some truly renewable ways of producing it, but it is most often produced by steam reformulating natural gas, a process that spits a fair amount of greenhouse gas into the atmosphere.

Honda hasn’t said what the lease on a Clarity will run you, but says the MSRP will be $63,000.

Subsidies or tax breaks like those offered for electric vehicles can blunt the high cost of the vehicles and win over consumers.

It’s a safe bet that the Clarity is headed to the US eventually, but Honda hasn't said when.

The entire point of this car—an idea Honda’s been kicking around for nearly three decades—is the hydrogen fuel cell.

That stack of cells will produce about 175 horsepower, and sent the car more than 300 miles between refueling stops.

Hydrogen is the most abundant element in the universe and there are some truly renewable ways of producing it, but it is most often produced by steam reformulating natural gas, a process that spits a fair amount of greenhouse gas into the atmosphere.

Honda hasn’t said what the lease on a Clarity will run you, but says the MSRP will be $63,000.

Subsidies or tax breaks like those offered for electric vehicles can blunt the high cost of the vehicles and win over consumers.

It’s a safe bet that the Clarity is headed to the US eventually, but Honda hasn't said when.

Honda, it turns out, is serious about this hydrogen fuel cell thing.

On Tuesday, the Japanese automaker unveiled the production version of its Clarity Fuel Cell sedan, which it will begin leasing to customers in Japan in March. It's a handsome enough car, vaguely futuristic, with a hint of Tesla's Model S.

But the styling is almost beside the point; the entire point of this car—an idea Honda's been kicking around for nearly three decades—is the hydrogen fuel cell, about the size of a V6 engine and stuffed under the hood, that keeps it going. That stack of cells will produce about 175 horsepower, and send the car more than 300 miles between refueling stops.

Automakers, especially Japanese and German automakers, love fuel cells. There's a lot to love about them. They combine all the benefits of battery electric vehicles like the Tesla Model S and Nissan Leaf—zero tailpipe emissions, excellent torque—without the drawbacks of limited range or waiting around for your battery to charge.

But there are some downsides, the most glaring of which is the acute lack of stations offering hydrogen. Hydrogen is the most abundant element in the universe and there are some truly renewable ways of producing it, but it is most often produced by steam reformulating natural gas, a process that spits a fair amount of greenhouse gas into the atmosphere. What's more, there's not much infrastructure for moving the stuff around once it's produced.

None of these problems is insurmountable. The California Fuel Cell Partnership claims 68 strategically placed stations would be enough to support 10,000 hydrogen cars in the San Francisco Bay Area, Los Angeles, and for drives between the two. At the moment, there are exactly two that are open to the public, with a third set to open this week (there are about 8,000 gas stations in the state). To be fair, dozens more are in the pipeline, but solving the infrastructure problem will take a lot of time and money.

That's the thing about hydrogen—everything about it is expensive. Honda hasn't said what the lease on a Clarity will run you, but says the MSRP will be $63,000. Toyota's fuel cell vehicle, the Mirai, costs $57,000. That kind of money gets you a new Corvette or puts you within striking distance of a second-hand Tesla Model S. Fuel cell vehicles are expensive because the underlying technology is expensive. Yes, that could change with economies of scale, but getting there will take time.

The situation is a little better in Japan, where the government subsidizes the cars and the infrastructure to support them. Still, the country has just 81 hydrogen fueling stations, according to Bloomberg Business, and about 34,000 gas stations. One Mirai driver told Bloomberg Business he loves his car, but must plan around the fact that the fueling spot near his Tokyo home closes at 5 pm.

None of this is to say fuel cells don't have their place. They make a lot of sense in fleet applications—which may be why Honda is offering the Clarity only to government agencies and "business customers" for the first year—and in big vehicles like city buses, which always refuel at the same place.

The problems can be resolved, of course. Subsidies or tax breaks like those offered for electric vehicles can blunt the high cost of the vehicles and win over consumers. More stations can be built, and hydrogen production can be increased. Making the case for such a strategy in the US is hard when gas is going for an average of $2.19 a gallon, but the math changes when you consider fuel prices inevitably will go up and the fact we've got to deal with climate change.

Honda isn't the only company pushing the tech. Toyota started selling the Mirai at eight California dealerships in July, and Mercedes-Benz offers its F-Cell in Los Angeles and San Francisco. Politics plays a role in this, too, because the California Air Resources Board requires automakers to offer a specific number of zero-emissions vehicles for sale each year.

For that reason, it's a safe bet that the Clarity is headed to the US eventually (Honda leased an earlier version, the FCX Clarity, in California for awhile). For now, it's being offered only in Japan, and only to those who live near a fueling station. Potential customers must complete an application and do a phone interview before forking over their cash, as clear a sign as any that this technology's not ready for the mass market.